Recently, semiconductor devices tend to be highly integrated, and a space between wirings has been miniaturized according to the high integration trend. This leads to an increase of electric capacity between the wirings, degrading a general speed of a signal. Thus, the permittivity between the wirings is required to be as low as possible.
As one method for realizing low permittivity, an air gap structure in which a void is formed between wirings has been reviewed. As a method of forming a void using an air gap structure, for example, a method of etching between wirings has been used. For example, a method of forming an air gap is disclosed in the related art.
However, misalignment may occur when performing patterning due to the issue of processing accuracy. This causes a degradation of circuit characteristics.